1. Field of the Inventions
The present inventions relate generally to mounting systems for eyewear, and more specifically to methods and apparatuses for mounting and retaining optical lenses.
2. Description of the Related Art
A wide variety of improvements have been made in recent years in the eyewear field, particularly with respect to eyewear intended for use in active sports or as fashion sunglasses. These eyewear designs provide a variety of functional improvements, such as maximizing interception of peripheral light, reducing optical distortion and increasing the wearer's comfort level, compared to previous active sport eyewear.
A continuing objective in the field of high quality eyewear, particularly that is intended for use in high speed action sports, is minimizing distortion introduced by the eyewear. Distortion may be introduced by any of a variety of influences, such as poor construction materials for the optical portion of the lens and inferior polishing and/or molding techniques for the lens. In addition, optical distortion can result from the interaction of the lens with the frame, such as changes in the shape of the lens orbital or poor orientation of the lens with respect to the wearer's normal line of sight.
Eyeglass systems which use a polymeric or metal wire frame are especially susceptible to bending and flexing due to a variety of environmental causes such as impact, storage-induced forces, forces resulting from the assembly process of the eyewear, and exposure to sunlight and heat. Flexing of the lens or uncontrolled deviation of the orientation of one lens with respect to the other or with respect to the earstems can undesirably change the optical characteristics of the eyeglasses, whether the optical lens is corrective (prescription) or noncorrective.
Additionally, many eyewear systems are assembled in which the lens is retained using an interference fit. Dual lens eyewear comprises a frame having a pair of orbitals that support lenses of the eyeglasses. The frame is usually formed as a single component that is later hingedly attached to left and right earstems that allow the eyeglasses to be worn by a user. In some cases, the left and right orbitals generally continuously surround the respective left and right lenses. In order to accommodate the lenses in the orbitals of the frame, the orbitals may include a groove that runs within the perimeter of the orbital. The bottom of the groove is generally formed to match the perimeter geometry of the lens. During assembly of the eyeglass, the lens is forcibly inserted into the groove of the orbital to produce a very tight interference fit. Unfortunately, that deformation can produce optical distortions or other unwanted stresses on the lenses.
A further consideration in eyeglass design is the ease of interchangeability of the lens. In dual lens eyeglasses having a continuous annular orbital, for example, removal of the lens such as for replacement is difficult and often impossible for the end user. Accordingly, there remains a need for further improvement in various aspects of eyeglass lens retention assemblies.